Photographic camera lens system adjusting mechanism



350-420 SR k Dbl-(UH KLJ-UN T 2 a C 2 y 1957 o. J. BLOOMBERG arm.2,797,618 X 2 2 '4 PHOTOGRAPHIC CAMERA LENS SYSTEM ADJUSTING MECHANISM Xa Filed Dec. 19, 1955 :5 Sheets-Sheet 1 /Z ap/v/ez 6400416586 Jo V E.PO/VD I N V EV TORS y 1957 o. J. BLOOMBERG ETAL 2,797,618

PHOTOGRAPHIC CAMERA LENS SYSTEM ADJUSTING MECHANISM Filed Dec. 19, 19553 Shets-Sheet 2 ppm/4 J. 54 00/1/5625 JOA A E BOA 0 l N V EN T0115 .56 v:76. 5. WM

PHOTOGRAPHIC CAMERA LENS SYSTEM ADJUSTING MECHANISM Filed Dec. 19, was

July 2, 1957 n. J. BLOOMBERG ETAL 3 Sheets-Sheet 3 paw/4 5400415596 JOHN5. 0/1/0 mmvroxs BYZZ- f United States Patent PHOTOGRAPHIC CAMERA LENSSYSTEM ADJUSTING MECHANISM Daniel J. Bloomberg, Encino, and John E.Pond, North Hollywood, Calif., assignors to Republic Productions, Inc.,a corporation of New York Application December 19, 1955, Serial No.553,967

14 Claims. (Cl. 88-57) This invention relates to a photographic lenssystem, and particularly to an anamorphotic lens attachment for standardmotion picture cameras and the adjusting mechanism therefor.

In the art of motion picture production, it has been found desirable tocompress the scene being photographed in a horizontal direction and toreversibly expand the scene in this direction upon projection to a widescreen.

Many types of optical systems for accomplishing this purpose have beendesigned, these prior systems using intricate and complex optical unitsfor compressing the image during the photographing of the scenes. Thepresent invention is directed to an anamorphotic lens adjunct orattachment to a standard motion picture camera which permits the scenebeing photographed to'be compressed to the desired aspect ratio. Theattachment permits the adjustment of the anamorphotic optical unit to afixed vertical, horizontal, and axial position, depending upon theoptical axis and focal length of the standard camera lens, and then tovariably adjust the focus of the combination of the anamorphotic lensunit and the standard camera lens unit to the distance of the scene tobe photographed. The latter adjusting mechanism includes a rack andpinion for moving the anamorphotic lens to adjust the focus thereof,together with various cams, each of which is suitable for a lens unit ofa certain focal length. Backlash has been avoided by the use of amechanical combination of rotary cam and linear rack which may beadjusted to its driven gear. With the anamorphotic unit removed, thestandard camera will function in its normal manner.

The principal object of the invention, therefore, is to facilitate thephotographing of compressed images on motion picture film.

Another object of the invention is to provide an attachment or adjunctto a standard motion picture camera for producing compressed images onmotion picture film.

A further object of the invention is to provide an anamorphotic lens andstandard lens combination for improving the photographing of compressedimage and the adjusting mechanism therefor.

A still further object of the invention is to provide an improvedadjusting mechanism for an anamorphotic lens attachment combined with astandard motion picture camera.

The novel features which are believed to be characteristic of thisinvention, both as to the manner of its organization and the mode of itsoperation, will be better understood from the following description whenread in conjunction with the accompanying drawings, in which:

Fig. 1 is a plan view of the front end of a standard commercial motionpicture camera with an anamorphotic lens attachment in position;

Fig. 2 is a cross-sectional view taken along the line 2-2 of Fig. 1;

Fig. 3 is an end view of the anamorphotic lens attachment taken alongthe line 3-3 of Fig. 2;

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Fig. 4 is a detail view taken along the line 4-4 of Fig. 3;

Fig. 5 is a detail view taken along the line 5-5 of Fig. 3; and

Fig. 6 is a detail view taken along the line 6-6 of Fig. 3.

Referring now to the drawings in which the same reference numeralsidentify the same elements, the end of a standard motion picture camera5 is shown with an optical unit 6 having a ring gear 7 for adjusting thefocus thereof. The ring gear 7 is in mesh with a wide intermediate gear9, which, in turn, is in mesh with a drive gear 10. The gear 9 is wideto permit gear 7 to move axially along the surface thereof during thefocusing adjustment. The gear 10 is rotated by a knurled hand wheel 12having an indicia disc 13 and a pointer support 14. The shaft 18,rotated by the wheel 12, has a gear 19 thereon in mesh with a gear 20 ona shaft 21. The drive gear 10 is mounted on the shaft 21 and rotatedthereby. Thus, to focus the lens unit 6, the wheel 12 is rotated, whichmoves the lens unit 6 axially to focus upon any particular scene. Asafety stop 8 protects against overtravel of lens unit 6. The equipmentjust described is the focusing mechanism for camera 5 when used alone.

To support the anamorphotic lens unit shown generally at 23 is a webbracket shown generally at 24, and which is attached to the camera 5.The bracket 24 is horizontally adjustable on standard dovetail ways onits base 22 by an eccentric 25, after which it is locked by a screw 30.The bracket 24 has a web 28 and a face plate 29 in which are dovetailways for mounting a horizontally slidable block 31. This permits theanamorphotic lens unit 23 to be moved axially to positions determined byspring biased pins 34 and a stop pin 35, depending upon the focal lengthof the standard camera lens unit 6 being used at any particular time.The block 31 has vertical dovetail ways for vertically adjusting amounting ring 32 which is integral with a dovetailed boss 36 in the waysof block 31. The ring 32 supports the anamorphotic lens unit 23. Thevertical adjustment is made with a screw 37.

Thus, to align the optical axis of the unit 23 with respect to aparticular lens unit 6 of a standard commercial camera, the bracket 24is moved horizontally on the ways in base plate 22 attached to thecamera and vertical by ring boss 36 in the ways of block 31. To adjustthe axial position of the unit 23 with respect to a certain lens unit 6,the block 31 is moved horizontally in the ways of face plate 29.

Since the anamorphotic lens of unit 23 compresses the in the key bracket73 and a notch 76 in nut 72. Screw I 74 is in an elongated slot inbracket 73 for rotating the lens within the limits of the slot. Alocking ring 78 is attached to nut 72 by screws such as shown at 79 tohold the anamorphotic lens securely within its mounting ring 32. Atelescoping sunshade is shown at 80.

The horizontal, vertical, and rotational adjustments just describednormally remain fixed after once made. The axial adjustment is madewhenever the camera lens unit 6 is changed.

The focusing mechanism for any particular scene will now be described.The unit 23 has a ring gear 39 which is in mesh with a pinion gear 40mounted on a shaft 41 rotatable on bearings 42. The shaft 41 is held inposition diameter one-half that of gear 40 to provide the necessaryrelationship between the angle of rotation of a driving cam 63, movementof rack 58, and rotation of gear 39. The rack 58 is in mesh with gear56, the rack being adjusted to the diametrical pitch of gear 56 by thepressure of ball bearings 43 and 53 ecentrically mounted on shafts suchas shown at 48, held in any adjusted position by a set screw 49. The twobearings are provided on each side of gear 56. A dustproof plate 45seals the bearings 42, gear 56, and rack 58. As shown in Fig. 4 byscrews 57, pressure is applied through a plate to the ends of the teethof rack 58 to maintain it in proper alignment with gear 56 and theoperating center of cam 63 and cam follower 59 in groove 62 of the cam.

To maintain the cam follower 'end of rack 58 in alignment duringrotation of the cam, a ball bearing 60, mounted on the end of the rack,rides on a plate 61. The cam 63 is mounted on a spline nut 65 which isrotatable in a bearing 67 held in housing 46 and driven by a spline 64.The assembly is held together by a lock nut 68, while the cam 63 ispositioned with respect to spline nut 65 by a pin 70 which is so locatedthat the root diameter of the groove 62, to provide the infinitefocusing position, is always at the proper point. A nut 69 holds the cam63 on the spline nut 65. This assembly permits cams with difierentshaped grooves to be readily interchanged when different lenscombinations are used. The spline permits axial movement of the focusingmechanism when different lens combinations are used. The spline 64 isconnected to shaft 21 by a double universal joint 71.

As mentioned above, the anamorphotic lens unit 23 is rotatable fororientation and shifted axially without rotation during focusing. Toadjust the rack position with respect to the cam groove and gear 39after the orientation adjustment, the mechanism to the left in Fig. isprovided. This unit is a friction connection between the shaft 41 andgear 40. The shaft 41 has two diametrically opposite radial holes inwhich are pins 50 movable axially in the holes by a pointed set screw 51threaded in the end of shaft 41. Thus, the gear 40 can be released fromshaft 41 during the rotation of the lens unit 23 which permits the rackto remain in its proper position. After the lens is oriented, the screw51 is turned to bring the ends of the pins 50 into pressure contact withthe gear 40. To lock screw 51, a nut 52 is threaded on the screw andbears against a cup washer 81, which, in turn, bears against the gear40.

The special cam and rack combination provides reversible action withinthe limits of rotation of the cam, v

each cam varying in accordance with the lens being used on the standardcamera. Each cam groove must permit the anamorphotic lens to be focusedbetween infinity and' approximately five feet for each lens unit used onthe standard camera, which are adjustable over different distanceswithin the same limits, depending on their focal lengths. Since accuracyof adjustment of the focus of the lens components in compressed imagephotography is critical in the production of good quality images, theabove-described initial and varying adjustments have been provided. Thefocusing adjustments of both lens units are under control of a singleband wheel 12, while the mechanism can be quickly changed to accommodatedifferent lens combinations.

We claim:

1. A photographic lens adjusting mechanism comprising a lens unitadapted to be attached to a camera having a lens, means for fixedlyadjusting the optical axis of said lens unit to a predetermined positionwith respect to said camera lens, and means for variably adjusting saidlens unit along its optical axis with respect to said camera lens, saidlast mentioned means including a ring gear on said lens unit, a piniondrive gear in mesh with said lens unit ring gear, a rack for rotatingsaid pinion drive gear, a cam having a spiral groove therein of apredetermined shape, the bottom of said groove being in a plane, a

connection between the end of said rack and said cam, and means forrotating said cam for rotating said lens unit ring gear to variablyadjust said lens unit along its optical axis.

2. A photographic lens adjusting mechanism in accordance with claim 1 inwhich said first mentioned means includes a bracket having dovetail wayson said camera for adjusting the optical axis of said lens unit in onedirection perpendicular to said axis, and a block intermediate saidbracket and said lens unit for adjusting the optical axis of said lensunit in another direction perpendicular to said first mentionedadjustment and to said optical axis.

3. A photographic camera system comprising a first lens unit, a geartrain for rotating said first lens unit for adjusting the focus thereof,a drive shaft for rotating said gear train, a second lens unit, meansfor adjusting the optical axis of said second gear unit to coincide withthe optical axis of said first lens unit, and means for adjusting thefocus of said second lens unit simultaneously with the adjustment of thefocus of said first lens unit, said means including a gear on saidsecond lens unit, a gear train including a pair of gears, one of saidpair of gears being in mesh with said second lens unit gear, a commonshaft for said pair of gears, a rack in mesh with the other of said pairof gears, a cam mounted on said first mentioned gear train shaft, andmeans for connecting said cam to said rack for rotation of said secondlens gear with the rotation of said first mentioned gear train for saidfirst lens unit.

4. A photographic camera system in accordance with claim 3 in which saidcam has a groove therein and said rack has a bearing member mounted insaid groove, a portion of said drive shaft being splined to permitmovement of said focus adjusting means for said second lens unitparallel with the optical axis of said lens units.

5. A photographic camera system in accordance with claim 4 in whichmeans are provided in contact with said rack for maintaining said rackin a predetermined path of movement during rotation of said cam.

6. A photographic camera system in accordance with claim 3 in whichmeans are provided for attaching and detaching said first mentioned oneof said pair of gears for said second lens unit from said common shaftto permit rotation of said gear on said second lens when said rack isstationary.

7. A lens unit attachment for a standard motion picture camera having acertain standard lens unit to provide contracted images, said attachmentcomprising an anamorphotic lens unit, means for mounting said lens unitto said camera, said means including means for fixedly adjusting theoptical axis of said anamorphotic lens unit to coincide with the axis ofsaid camera lens unit, means for fixedly adjusting said anamorphoticlens unit to a definite position along its optical axis in accordancewith the particular standard lens unit, means for variably adjusting thefocus of said camera lens unit, said means including a rotatable shaft,an extension for said shaft, and focus adjusting mechanism for saidanamorphotic lens unit mounted on and rotatable by said extension ofsaid shaft, said mechanism including a cam having a groove therein of ashape depending on the particular lens unit of said camera, a rackmovable rectilinearly by said cam, a gear rotatable by said rack, and agear on said anamorphotic lens unit in mesh with a gear rotated bymovement of said rack.

8. A lens unit attachment in accordance with claim 7 in which a gear isprovided in mesh with said rack and a common shaft is provided for saidgear in mesh with said rack and said gear in mesh with said lens gear,and means being provided for connecting and disconnecting said gear inmesh with said lens unit gear to and from said common shaft.

9. A lens unit attachment in accordance with claim 7 in which areprovided a connecting means between said cam and said rack, said meansincluding a bearing mounted in a groove in said cam, means beingprovided to adjust the path of said rack with respect to the gear inmesh therewith and said groove in said cam.

10. A lens unit attachment in accordance with claim 7 in which saidmounting means for said anamorphotic lens unit includes means foradjusting the fixed rotational position of the lens in said unit, saidfocus adjusting mechanism transporting said lens along its optical axis.

11. A lens unit attachment in accordance with claim 8 in which saidconnecting and disconnecting means are pins in radial openings in saidcommon shaft adapted to bear against said gear in mesh with said lensgear, threaded means being provided in said common shaft to move saidpins in said openings.

12. A lens unit attachment in accordance with claim 7 in which saidmounting and fixedly adjusting means for said anamorphotic lens unitincludes a bracket adjustable in one direction on said camera and aholder for said anamorphotic lens unit adjustable on said bracket atright angles to the direction of adjustment of said bracket on saidcamera and along the optical axis of said lens units.

13. A lens unit attachment for a standard motion picture camera, saidcamera being adapted to use lens units of different focal lengths, saidlens unit attachment and said camera lens units providing contractedimages, comprising an anamorphotic lens unit, means for mounting saidanamorphotic lens unit to said camera, said means including means forfixedly adjusting the optical axis of said anamorphotic lens unit tocoincide with the optical axis of any one of said lens units of saidcamera, means for fixedly adjusting said anamorphotic lens unit to adefinite position along its optical axis in accordance with the focallength of any particular lens unit of said camera, means for variablyadjusting the focus of said camera lens unit, said means including arotatable shaft, and a focus adjusting mechanism for said anamorphoticlens unit rotatable by said shaft, said mechanism including a cam havinga groove therein of a shape depending on the particular lens unit ofsaid camera, a ring gear on said anamorphotic lens unit, and means forinterconnecting said ring gear with said shaft.

14. A lens unit attachment in accordance with claim 13 in which saidlast-mentioned means includes a pair of interconnected gears and a rack,one of said pair of gears being in mesh with said ring gear of saidanamorphotic lens unit and the other of said pair of gears being in meshwith said rack, the end of said rack being connected in said cam groove.

References Cited in the file of this patent UNITED STATES PATENTS1,879,737 Del Riccio Sept. 27, 1932 1,947,669 Warmisham et al. Feb. 20,1934 2,159,394 Mellor et al. May 23, 1939 2,165,341 Capstafi et al. July11, 1939 2,720,817 Mills Oct. 18, 1955

